Hafnium tantalum titanium oxide films

ABSTRACT

Embodiments of a dielectric layer containing a hafnium tantalum titanium oxide film structured as one or more monolayers include the dielectric layer disposed in a transistor. An embodiment may include forming a hafnium tantalum titanium oxide film using a monolayer or partial monolayer sequencing process such as reaction sequence atomic layer deposition.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/208,946, filed Aug. 12, 2011, which is a continuation application ofU.S. application Ser. No. 12/563,596, filed Sep. 21, 2009, now issued asU.S. Pat. No. 7,999,334, which is a divisional application of U.S.application Ser. No. 11/297,741, filed Dec. 8, 2005, now U.S. Pat. No.7,592,251, which applications are all incorporated by reference hereintheir entirety.

TECHNICAL FIELD

This application relates generally to semiconductor devices and devicefabrication.

BACKGROUND

The semiconductor device industry has a market driven need to reduce thesize of devices used in products such as processor chips, mobiletelephones, and memory devices such as dynamic random access memories(DRAMs). Currently, the semiconductor industry relies on the ability toreduce or scale the dimensions of its basic devices. This device scalingincludes scaling dielectric layers in devices such as, for example,capacitors and silicon based metal oxide semiconductor field effecttransistors (MOSFETs) and variations thereof, which have primarily beenfabricated using silicon dioxide. A thermally grown amorphous SiO2 layerprovides an electrically and thermodynamically stable material, wherethe interface of the SiO2 layer with underlying silicon provides a highquality interface as well as superior electrical isolation properties.However, increased scaling and other requirements in microelectronicdevices have created the need to use other materials as dielectricregions in a variety of electronic structures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates features for an embodiment of a method to form ahafnium tantalum titanium oxide film using atomic layer deposition.

FIG. 2 shows an embodiment of a transistor having a dielectric layercontaining a hafnium tantalum titanium oxide film.

FIG. 3 shows an embodiment of a floating gate transistor having adielectric layer containing a hafnium tantalum titanium oxide film.

FIG. 4 shows an embodiment of a capacitor having a dielectric layercontaining a hafnium tantalum titanium oxide film.

FIG. 5 depicts an embodiment of a dielectric layer having multiplelayers including a hafnium tantalum titanium oxide layer.

FIG. 6 is a simplified diagram for an embodiment of a controller coupledto an electronic device having a dielectric layer containing a hafniumtantalum titanium oxide film.

FIG. 7 illustrates a diagram for an embodiment of an electronic systemhaving devices with a dielectric film containing a hafnium tantalumtitanium oxide film.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawingsthat show, by way of illustration, specific aspects and embodiments inwhich the present invention may be practiced. These embodiments aredescribed in sufficient detail to enable those skilled in the art topractice the present invention. Other embodiments may be utilized andstructural, logical, and electrical changes may be made withoutdeparting from the scope of the present invention. The variousembodiments are not necessarily mutually exclusive, as some embodimentscan be combined with one or more other embodiments to form newembodiments.

The terms wafer and substrate used in the following description includeany structure having an exposed surface with which to form an integratedcircuit (IC) structure. The term substrate is understood to include asemiconductor wafer. The term substrate is also used to refer tosemiconductor structures during processing, and may include other layersthat have been fabricated thereupon. Both wafer and substrate includedoped and undoped semiconductors, epitaxial semiconductor layerssupported by a base semiconductor or insulator, as well as othersemiconductor structures well known to one skilled in the art. The termconductor is understood to generally include n-type and p-typesemiconductors, and the term insulator or dielectric is defined toinclude any material that is less electrically conductive than thematerials referred to as conductors. The following detailed descriptionis, therefore, not to be taken in a limiting sense, and the scope of thepresent invention is defined only by the appended claims, along with thefull scope of equivalents to which such claims are entitled.

To scale a dielectric region to minimize feature sizes to provide highdensity electronic devices, the dielectric region typically should havea reduced equivalent oxide thickness (t_(eq)). The equivalent oxidethickness quantifies the electrical properties, such as capacitance, ofthe dielectric in terms of a representative physical thickness. t_(eq)is defined as the thickness of a theoretical SiO₂ layer that would berequired to have the same capacitance density as a given dielectric,ignoring leakage current and reliability considerations.

A SiO₂ layer of thickness, t, deposited on a Si surface will have at_(eq) larger than its thickness, t. This t_(eq) results from thecapacitance in the surface on which the SiO₂ is deposited due to theformation of a depletion/inversion region. This depletion/inversionregion can result in t_(eq) being from 3 to 6 Angstroms (Å) larger thanthe SiO₂ thickness, t. Thus, with the semiconductor industry driving tosomeday scale a gate dielectric equivalent oxide thickness to less than10 Å, the physical thickness requirement for a SiO₂ layer used for agate dielectric may need to be approximately 4 to 7 Å. Additionalrequirements on a SiO₂ layer would depend on the electrode used inconjunction with the SiO₂ dielectric. Using a conventional polysiliconelectrode may result in an additional increase in t_(eq) for the SiO₂layer. This additional thickness may be eliminated by using a metalelectrode, though such metal electrodes are not universally used for alldevices. Thus, future devices would be designed towards a physical SiO₂dielectric layer of about 5 Å or less. Such a small thicknessrequirement for a SiO₂ oxide layer creates additional problems.

Silicon dioxide is used as a dielectric layer in devices, in part, dueto its electrical isolation properties in a SiO₂—Si based structure.This electrical isolation is due to the relatively large band gap ofSiO₂ (8.9 eV), making it a good insulator from electrical conduction.Significant reductions in its band gap may eliminate it as a materialfor a dielectric region in an electronic device. As the thickness of aSiO₂ layer decreases, the number of atomic layers, or monolayers of thematerial decreases. At a certain thickness, the number of monolayerswill be sufficiently small that the SiO₂ layer will not have a completearrangement of atoms as in a larger or bulk layer. As a result ofincomplete formation relative to a bulk structure, a thin SiO₂ layer ofonly one or two monolayers may not form a full band gap. The lack of afull band gap in a SiO₂ dielectric may cause an effective short betweenan underlying Si electrode and an overlying polysilicon electrode. Thisundesirable property sets a limit on the physical thickness to which aSiO₂ layer can be scaled. The minimum thickness due to this monolayereffect is thought to be about 7-8 Å. Therefore, for future devices tohave a t_(eq) less than about 10 Å, other dielectrics than SiO₂ need tobe considered for use as a dielectric region in such future devices.

In many cases, for a typical dielectric layer, the capacitance isdetermined as a capacitance for a parallel plate capacitor: C=κ∈0A/t,where κ is the dielectric constant, ∈0 is the permittivity of freespace, A is the area of the capacitor, and t is the thickness of thedielectric. The thickness, t, of a material is related to its t_(eq) fora given capacitance, with SiO₂ having a dielectric constant κ_(ox)=3.9,as

t=(κ/κ_(ox))t _(eq)=(κ/3.9)t _(eq).

Thus, materials with a dielectric constant greater than that of SiO₂will have a physical thickness that can be considerably larger than adesired t_(eq), while providing the desired equivalent oxide thickness.For example, an alternate dielectric material with a dielectric constantof 10 could have a thickness of about 25.6 Å to provide a t_(eq) of 10Å, not including any depletion/inversion layer effects. Thus, a reducedequivalent oxide thickness for transistors can be realized by usingdielectric materials with higher dielectric constants than SiO₂.

The thinner equivalent oxide thickness required for lower deviceoperating voltages and smaller device dimensions may be realized by asignificant number of materials, but additional fabricating requirementsmake determining a suitable replacement for SiO₂ difficult. The currentview for the microelectronics industry is still for Si based devices.This may require that the dielectric material employed be grown on asilicon substrate or a silicon layer, which places significantconstraints on the substitute dielectric material. During the formationof the dielectric on the silicon layer, there exists the possibilitythat a small layer of SiO₂ could be formed in addition to the desireddielectric. The result would effectively be a dielectric layerconsisting of two sublayers in parallel with each other and the siliconlayer on which the dielectric is formed. In such a case, the resultingcapacitance would be that of two dielectrics in series. As a result, thet_(eq) of the dielectric layer would be the sum of the SiO₂ thicknessand a multiplicative factor of the thickness, t, of the dielectric beingformed, written as

t _(eq) =t _(SiO2)+(κ_(ox)/κ)t.

Thus, if a SiO₂ layer is formed in the process, the t_(eq) is againlimited by a SiO₂ layer. In the event that a barrier layer is formedbetween the silicon layer and the desired dielectric in which thebarrier layer prevents the formation of a SiO₂ layer, the t_(eq) wouldbe limited by the layer with the lowest dielectric constant. However,whether a single dielectric layer with a high dielectric constant or abarrier layer with a higher dielectric constant than SiO₂ is employed,the layer interfacing with the silicon layer should provide a highquality interface.

One of the advantages of using SiO₂ as a dielectric layer in a devicehas been that the formation of the SiO₂ layer results in an amorphousdielectric. Having an amorphous structure for a dielectric may reduceproblems of leakage current associated with grain boundaries inpolycrystalline dielectrics that provide high leakage paths.Additionally, grain size and orientation changes throughout apolycrystalline dielectric can cause variations in the film's dielectricconstant, along with uniformity and surface topography problems.Typically, materials having a high dielectric constant relative to SiO₂also have a crystalline form, at least in a bulk configuration. The bestcandidates for replacing SiO₂ as a dielectric in a device are those thatcan be fabricated as a thin layer with an amorphous form and that havehigh dielectric constants.

In an embodiment, a hafnium tantalum titanium oxide dielectric film maybe formed using atomic layer deposition (ALD). Forming such a dielectricfilm using atomic layer deposition may allow control of transitionsbetween material layers. As a result of such control, atomic layerdeposited hafnium tantalum titanium oxide dielectric films can have anengineered transition with a substrate surface. Embodiments includestructures for capacitors, transistors, memory devices, and electronicsystems with a hafnium tantalum titanium oxide film structured as one ormore monolayers, and methods for forming such structures.

ALD, also known as atomic layer epitaxy (ALE), is a modification ofchemical vapor deposition (CVD) and is also called “alternativelypulsed-CVD.” In ALD, gaseous precursors are introduced one at a time tothe substrate surface mounted within a reaction chamber (or reactor).This introduction of the gaseous precursors takes the form of pulses ofeach gaseous precursor. In a pulse of a precursor gas, the precursor gasis made to flow into a specific area or region for a short period oftime. Between the pulses, the reaction chamber may be purged with a gas,where the purging gas may be an inert gas. Between the pulses, thereaction chamber may be evacuated. Between the pulses, the reactionchamber may be purged with a gas and evacuated.

In a chemisorption-saturated ALD (CS-ALD) process, during the firstpulsing phase, reaction with the substrate occurs with the precursorsaturatively chemisorbed at the substrate surface. Subsequent pulsingwith a purging gas removes precursor excess from the reaction chamber.

The second pulsing phase introduces another precursor on the substratewhere the growth reaction of the desired film takes place. Subsequent tothe film growth reaction, reaction byproducts and precursor excess arepurged from the reaction chamber. With favourable precursor chemistrywhere the precursors adsorb and react with each other aggressively onthe substrate, one ALD cycle can be performed in less than one second inproperly designed flow type reaction chambers. Typically, precursorpulse times range from about 0.5 sec to about 2 to 3 seconds. Pulsetimes for purging gases may be significantly longer, for example, pulsetimes of about 5 to about 30 seconds.

In ALD, the saturation of all the reaction and purging phases makes thegrowth self-limiting. This self-limiting growth results in large areauniformity and conformality, which has important applications for suchcases as planar substrates, deep trenches, and in the processing ofporous silicon and high surface area silica and alumina powders. Atomiclayer deposition provides control of film thickness in a straightforwardmanner by controlling the number of growth cycles.

The precursors used in an ALD process may be gaseous, liquid or solid.However, liquid or solid precursors should be volatile. The vaporpressure should be high enough for effective mass transportation. Also,solid and some liquid precursors may need to be heated inside thereaction chamber and introduced through heated tubes to the substrates.The necessary vapor pressure should be reached at a temperature belowthe substrate temperature to avoid the condensation of the precursors onthe substrate. Due to the self-limiting growth mechanisms of ALD,relatively low vapor pressure solid precursors can be used, thoughevaporation rates may vary somewhat during the process because ofchanges in their surface area.

There are several other characteristics for precursors used in ALD. Theprecursors should be thermally stable at the substrate temperature,because their decomposition may destroy the surface control andaccordingly the advantages of the ALD method that relies on the reactionof the precursor at the substrate surface. A slight decomposition, ifslow compared to the ALD growth, may be tolerated.

The precursors should chemisorb on or react with the surface, though theinteraction between the precursor and the surface as well as themechanism for the adsorption is different for different precursors. Themolecules at the substrate surface should react aggressively with thesecond precursor to form the desired solid film. Additionally,precursors should not react with the film to cause etching, andprecursors should not dissolve in the film. Using highly reactiveprecursors in ALD contrasts with the selection of precursors forconventional CVD.

The by-products in the reaction should be gaseous in order to allowtheir easy removal from the reaction chamber. Further, the by-productsshould not react or adsorb on the surface.

In a reaction sequence ALD (RS-ALD) process, the self-limiting processsequence involves sequential surface chemical reactions. RS-ALD relieson chemistry between a reactive surface and a reactive molecularprecursor. In an RS-ALD process, molecular precursors are pulsed intothe ALD reaction chamber separately. A metal precursor reaction at thesubstrate is typically followed by an inert gas pulse to remove excessprecursor and by-products from the reaction chamber prior to pulsing thenext precursor of the fabrication sequence.

By RS-ALD, films can be layered in equal metered sequences that may allbe identical in chemical kinetics, deposition per cycle, composition,and thickness. RS-ALD sequences generally deposit less than a full layerper cycle. Typically, a deposition or growth rate of about 0.25 to about2.00 Å per RS-ALD cycle may be realized.

Processing by RS-ALD provides continuity at an interface avoiding poorlydefined nucleating regions that are typical for chemical vapordeposition (<20 Å) and physical vapor deposition (<50 Å), conformalityover a variety of substrate topologies due to its layer-by-layerdeposition technique, use of low temperature and mildly oxidizingprocesses, lack of dependence on the reaction chamber, growth thicknessdependent solely on the number of cycles performed, and ability toengineer multilayer laminate films with a resolution of one to twomonolayers. RS-ALD processes allow for deposition control on the orderof monolayers and the ability to deposit monolayers of amorphous films.

Herein, a sequence refers to the ALD material formation based on an ALDreaction of a precursor with its reactant precursor. For example,forming tantalum oxide from a TaCl5 precursor and water vapor, as itsreactant precursor, forms an embodiment of a tantalum/oxygen sequence,which can also be referred to as a tantalum sequence. In various ALDprocesses that form an oxide or a compound that contains oxygen, areactant precursor that contains oxygen is used to supply oxygen.Herein, a precursor that contains oxygen and that supplies oxygen to beincorporated in the ALD compound formed, which may be used in an ALDprocess with precursors supplying the other elements in the ALDcompound, is referred to as an oxygen reactant precursor. In the aboveexample, water vapor is an oxygen reactant precursor. An ALD cycle mayinclude pulsing a precursor, pulsing a purging gas for the precursor,pulsing a reactant precursor, and pulsing the reactant precursor'spurging gas. Further, in forming a layer of a metal species, an ALDsequence may deal with reacting a precursor containing the metal specieswith a substrate surface. A cycle for such a metal forming sequence mayinclude pulsing a purging gas after pulsing the precursor containing themetal species to deposit the metal. Additionally, deposition of asemiconductor material may be realized in a manner similar to forming alayer of a metal, given the appropriate precursors for the semiconductormaterial.

In an ALD formation of a compound having more than two elements, a cyclemay include a number of sequences to provide the elements of thecompound. For example, a cycle for an ALD formation of an ABO_(x)compound may include sequentially pulsing a first precursor/a purginggas for the first precursor/a first reactant precursor/the firstreactant precursor's purging gas/a second precursor/a purging gas forthe second precursor/a second reactant precursor/the second reactantprecursor's purging gas, which may be viewed as a cycle having twosequences. In an embodiment, a cycle may include a number of sequencesfor element A and a different number of sequences for element B. Theremay be cases in which ALD formation of an ABO_(x) compound uses oneprecursor that contains the elements A and B, such that pulsing the ABcontaining precursor followed by its reactant precursor onto a substratemay include a reaction that forms ABO_(x) on the substrate to provide anAB/oxygen sequence. A cycle of an AB/oxygen sequence may include pulsinga precursor containing A and B, pulsing a purging gas for the precursor,pulsing an oxygen reactant precursor to the A/B precursor, and pulsing apurging gas for the reactant precursor. A cycle may be repeated a numberof times to provide a desired thickness of the compound. In anembodiment, a cycle for an ALD formation of the quaternary compound,hafnium tantalum titanium oxide, may include sequentially pulsing afirst precursor/a purging gas for the first precursor/a first reactantprecursor/the first reactant precursor's purging gas/a secondprecursor/a purging gas for the second precursor/a second reactantprecursor/the second reactant precursor's purging gas/a thirdprecursor/a purging gas for the third precursor/a third reactantprecursor/the third reactant precursor's purging gas, which may beviewed as a cycle having three sequences. In an embodiment, a layersubstantially of a hafnium tantalum titanium oxide compound is formed ona substrate mounted in a reaction chamber using ALD in repetitivehafnium, tantalum, and titanium sequences using precursor gasesindividually pulsed into the reaction chamber. Alternatively, solid orliquid precursors can be used in an appropriately designed reactionchamber.

In an embodiment, a hafnium tantalum titanium oxide layer may bestructured as one or more monolayers. A film of hafnium tantalumtitanium oxide, structured as one or more monolayers, may have athickness that ranges from a monolayer to thousands of angstroms. Thefilm may be processed using atomic layer deposition. Embodiments of anatomic layer deposited hafnium tantalum titanium oxide layer have alarger dielectric constant than silicon dioxide. Such dielectric layersprovide a significantly thinner equivalent oxide thickness compared witha silicon oxide layer having the same physical thickness. Alternatively,such dielectric layers provide a significantly thicker physicalthickness than a silicon oxide layer having the same equivalent oxidethickness. This increased physical thickness aids in reducing leakagecurrent.

The term hafnium tantalum titanium oxide is used herein with respect toa compound that essentially consists of hafnium, tantalum, titanium, andoxygen in a form that may be stoichiometric, non-stoichiometric, or acombination of stoichiometric and non-stoichiometric. In an embodiment,hafnium tantalum titanium oxide may be formed substantially asstoichiometric hafnium tantalum titanium oxide. In an embodiment,hafnium tantalum titanium oxide may be formed substantially as anon-stoichiometric hafnium tantalum titanium oxide. In an embodiment,hafnium tantalum titanium oxide may be formed substantially as acombination of non-stoichiometric hafnium tantalum titanium oxide andstoichiometric hafnium tantalum titanium oxide. Herein, a hafniumtantalum titanium oxide compound may be expressed as HfTaTiO,HfTaTiO_(x), Hf_(x)Ta_(y)Ti_(z)O_(r), or other equivalent form. Theexpression HfTaTiO or its equivalent forms may be used to include astoichiometric hafnium tantalum titanium oxide. The expression HfTaTiOor its equivalent forms may be used to include a non-stoichiometrichafnium tantalum titanium oxide. The expression HfTaTiO or itsequivalent forms may be used to include a combination of astoichiometric hafnium tantalum titanium oxide and a non-stoichiometrichafnium tantalum titanium oxide. The expression HfO_(x) may be used toinclude a stoichiometric hafnium oxide. The expression HfO_(x) may beused to include a non-stoichiometric hafnium oxide. The expressionHfO_(x) may be used to include a combination of a stoichiometric hafniumoxide and a non-stoichiometric hafnium oxide. Expressions TaO_(y) andTiO_(r) may be used in the same manner as HfO_(x). In variousembodiments, a hafnium tantalum titanium oxide film may be doped withelements or compounds other than hafnium, tantalum, titanium, andoxygen.

In an embodiment, a HfTaTiO_(x) film may be structured as one or moremonolayers. In an embodiment, the HfTaTiO_(x) film may be constructedusing atomic layer deposition. Prior to forming the HfTaTiO_(x) filmusing ALD, the surface on which the HfTaTiO_(x) film is to be depositedmay undergo a preparation stage. The surface may be the surface of asubstrate for an integrated circuit. In an embodiment, the substrateused for forming a transistor may include a silicon or siliconcontaining material. In other embodiments, germanium, gallium arsenide,silicon-on-sapphire substrates, or other suitable substrates may beused. A preparation process may include cleaning the substrate andforming layers and regions of the substrate, such as drains and sources,prior to forming a gate dielectric in the formation of a metal oxidesemiconductor (MOS) transistor. Alternatively, active regions may beformed after forming the dielectric layer, depending on the over-allfabrication process implemented. In an embodiment, the substrate iscleaned to provide an initial substrate depleted of its native oxide. Inan embodiment, the initial substrate is cleaned also to provide ahydrogen-terminated surface. In an embodiment, a silicon substrateundergoes a final hydrofluoric (HF) rinse prior to ALD processing toprovide the silicon substrate with a hydrogen-terminated surface withouta native silicon oxide layer.

Cleaning immediately preceding atomic layer deposition aids in reducingan occurrence of silicon oxide as an interface between a silicon basedsubstrate and a hafnium tantalum titanium oxide dielectric formed usingthe atomic layer deposition process. The material composition of aninterface layer and its properties are typically dependent on processconditions and the condition of the substrate before forming thedielectric layer. Though the existence of an interface layer mayeffectively reduce the dielectric constant associated with thedielectric layer and its substrate interface layer, a SiO₂ interfacelayer or other composition interface layer may improve the interfacedensity, fixed charge density, and channel mobility of a device havingthis interface layer.

The sequencing of the formation of the regions of an electronic device,such as a transistor, being processed may follow typical sequencing thatis generally performed in the fabrication of such devices as is wellknown to those skilled in the art. Included in the processing prior toforming a dielectric may be the masking of substrate regions to beprotected during the dielectric formation, as is typically performed insemiconductor fabrication. In an embodiment, the unmasked regionincludes a body region of a transistor; however, one skilled in the artwill recognize that other semiconductor device structures may utilizethis process.

FIG. 1 illustrates features of an embodiment of a method to form ahafnium tantalum titanium oxide film using atomic layer deposition. Theindividual features labeled 110, 120, 130, and 140 may be performed invarious orders. Between each pulsing of a precursor used in an atomiclayer deposition process, a purging gas may be pulsed into the ALDreaction chamber. Between each pulsing of a precursor, the ALD reactorchamber may be evacuated using vacuum techniques as is known by thoseskilled in the art. Between each pulsing of a precursor, a purging gasmay be pulsed into the ALD reaction chamber and the ALD reactor chambermay be evacuated.

At 110, hafnium oxide may be formed by atomic layer deposition. Ahafnium-containing precursor is pulsed onto a substrate in an ALDreaction chamber. A number of precursors containing hafnium may be usedto provide the hafnium to a substrate for an integrated circuit. In anembodiment, a precursor containing hafnium may include anhydrous hafniumnitride, Hf(NO₃)₄. In an embodiment using a Hf(NO₃)₄ precursor on ahydrogen-terminated silicon, the substrate temperature may be maintainedat a temperature ranging from about 160° C. to about 180° C. In anembodiment, a hafnium precursor may include HfCl₄. In an embodimentusing a HfCl₄ precursor, the substrate temperature may be maintained ata temperature ranging from about 180° C. to about 600° C. In anembodiment using a HfCl₄ precursor, the substrate temperature may bemaintained at a temperature ranging from about 300° C. to about 940° C.In an embodiment, a hafnium precursor used may be HfI₄. In an embodimentusing a HfI₄ precursor, the substrate temperature may be maintained at atemperature of about 300° C. In various embodiments, after pulsing thehafnium-containing precursor and purging the reaction chamber of excessprecursor and by-products from pulsing the precursor, a reactantprecursor may be pulsed into the reaction chamber. The reactantprecursor may be an oxygen reactant precursor including, but not limitedto, one or more of water vapor, atomic oxygen, molecular oxygen, ozone,hydrogen peroxide, a water-hydrogen peroxide mixture, alcohol, ornitrous oxide. In various embodiments, use of the individualhafnium-containing precursors is not limited to the temperature rangesof the above embodiments. In addition, the pulsing of the hafniumprecursor may use a pulsing period that provides uniform coverage of amonolayer on the surface or may use a pulsing period that providespartial coverage of a monolayer on the surface during a hafniumsequence.

At 120, tantalum oxide may be formed by atomic layer deposition. Atantalum-containing precursor is pulsed to the substrate in the ALDreaction chamber. A number of precursors containing tantalum may be usedto provide the tantalum to the substrate. In an embodiment, a precursorcontaining tantalum may include a tantalum ethoxide, Ta(OC₂H₅)₅,precursor. In an embodiment, during pulsing of the precursor containingtantalum, the substrate may be held between about 150° C. and about 450°C. In an embodiment, the substrate may be held between about 250° C. andabout 325° C. In an embodiment, a tantalum halide such as TaCl₅ may beused as a precursor. In various embodiments, after pulsing thetantalum-containing precursor and purging the reaction chamber of excessprecursor and by-products from pulsing the precursor, a reactantprecursor may be pulsed into the reaction chamber. The reactantprecursor may be an oxygen reactant precursor including, but not limitedto, one or more of water vapor, atomic oxygen, molecular oxygen, ozone,hydrogen peroxide, a water-hydrogen peroxide mixture, alcohol, ornitrous oxide. In various embodiments, use of the individualtantalum-containing precursors is not limited to the temperature rangesof the above embodiments. In addition, the pulsing of the tantalumprecursor may use a pulsing period that provides uniform coverage of amonolayer on the surface or may use a pulsing period that providespartial coverage of a monolayer on the surface during a tantalumsequence.

At 130, titanium oxide may be formed by atomic layer deposition. Atitanium-containing precursor is pulsed to the substrate. A number ofprecursors containing titanium may be used to provide the titanium onthe substrate. In an embodiment, the titanium-containing precursor maybe TiCl₄. In an embodiment using a TiCl₄ precursor, the substratetemperature may be maintained at a temperature ranging from about 100°C. to about 500° C. In an embodiment using a TiCl₄ precursor, thesubstrate temperature may be maintained at a temperature of about 425°C. In an embodiment, a titanium precursor pulsed may be TiI₄. In anembodiment using a TiI₄ precursor, the substrate temperature may bemaintained between about 230° C. and about 490° C. In an embodiment, atitanium precursor pulsed may be anhydrous Ti(NO₃)₄. In an embodimentusing a Ti(NO₃)₄ precursor, the substrate temperature may be maintainedat a temperature ranging from less than 250° C. to about 700° C. In anembodiment, a titanium precursor pulsed may be titanium isopropoxide,also written as Ti(Oi-Pr)₄. In an embodiment using a Ti(Oi-Pr)₄precursor, the substrate temperature may be maintained at a temperatureranging from less than 250° C. to about 700° C. However, use of theindividual titanium precursors is not limited to the temperature rangesof the above embodiments. In various embodiments, after pulsing thetitanium-containing precursor and purging the reaction chamber of excessprecursor and by-products from pulsing the precursor, a reactantprecursor may be pulsed into the reaction chamber. The reactantprecursor may be an oxygen reactant precursor including, but are notlimited to, one or more of water vapor, atomic oxygen, molecular oxygen,ozone, hydrogen peroxide, a water-hydrogen peroxide mixture, alcohol, ornitrous oxide. In addition, the pulsing of the titanium precursor mayuse a pulsing period that provides uniform coverage of a monolayer onthe surface or may use a pulsing period that provides partial coverageof a monolayer on the surface during a titanium sequence.

In various embodiments, nitrogen may be used as a purging gas and acarrier gas for one or more of the sequences used in the ALD formationof HfO_(x), TaO_(y), and TiO_(z). Alternatively, hydrogen, argon gas, orother inert gases may be used as the purging gas. Excess precursor gasand reaction by-products may be removed by the purge gas. Excessprecursor gas and reaction by-products may be removed by evacuation ofthe reaction chamber using various vacuum techniques. Excess precursorgas and reaction by-products may be removed by the purge gas and byevacuation of the reaction chamber.

Atomic layer deposition of the individual components or layers ofHfO_(x), TaO_(y), and TiO_(z) allows for individual control of eachprecursor pulsed into the reaction chamber. Thus, each precursor ispulsed into the reaction chamber for a predetermined period, where thepredetermined period can be set separately for each precursor.Additionally, for various ALD formations, each precursor may be pulsedinto the reaction chamber under separate environmental conditions. Thesubstrate may be maintained at a selected temperature and the reactionchamber maintained at a selected pressure independently for pulsing eachprecursor. Appropriate temperatures and pressures may be maintained,whether the precursor is a single precursor or a mixture of precursors.

At 140, the hafnium oxide, the tantalum oxide, and the titanium oxideare annealed to form hafnium tantalum titanium oxide. In an embodiment,a laminated stack of alternating layers of TiO₂, TaO₂, and HfO₂ areformed prior to annealing. In various embodiments, the order of formingTiO_(x), TaO_(y), and HfO_(z) layers may be permutated. The annealingmay be conducted in a nitrogen ambient. In an embodiment, annealing maybe conducted in a nitrogen ambient having a small amount of oxygen. Inan embodiment, annealing may be performed by rapid thermal annealing(RTA) to form a HfTaTiO_(x) film. In an embodiment, annealing may beconducted at a temperature ranging from about 600° C. to about 900° C.for a period of time ranging from about 10 seconds to about 30 seconds.However, annealing is not limited to these temperatures, periods, orambient conditions.

In an embodiment, a layer of hafnium oxide, a layer of tantalum oxide,and a layer of titanium oxide are each grown by atomic layer depositionto a thickness such that annealing these layers at appropriatetemperatures essentially converts these layers to a layer of hafniumtantalum titanium oxide. In an embodiment, each layer of HfO_(x),TaO_(y), and TiO_(z) is formed to a thickness of 10 Å or less. In thevarious embodiments, the thickness of a hafnium tantalum titanium oxidefilm is related to the number of ALD cycles performed and the growthrate associated with forming each layer of HfO_(x), TaO_(y), andTiO_(z). As can be understood by those skilled in the art, particulareffective growth rates for the engineered hafnium tantalum titaniumoxide film can be determined during normal initial testing of the ALDsystem used in processing a hafnium tantalum titanium oxide dielectricfor a given application without undue experimentation.

In an embodiment, a HfTaTiO film may be grown to a desired thickness byrepetition of a process including atomic layer deposition of layers ofHfO_(x), TaO_(y), TiO_(z) followed by annealing. In an embodiment, abase thickness may be formed according to various embodiments such thatforming a predetermined thickness of a HfTaTiO film may be conducted byforming a number of layers having the base thickness. As can beunderstood by one skilled in the art, determining the base thicknessdepends on the application and can be determined during initialprocessing without undue experimentation. Relative amounts of hafnium,tantalum, and titanium in a HfTaTiO film may be controlled by regulatingthe relative thicknesses of the individual layers of HfO_(x), TaO_(y),TiO_(z) formed. In addition, relative amounts of hafnium, tantalum, andtitanium in a HfTaTiO film may be controlled by forming a layer ofHfTaTiO as multiple layers of different base thickness and by regulatingthe relative thicknesses of the individual layers of HfO_(x), TaO_(y),and TiO_(z) formed in each base layer.

In an alternative embodiment, an ALD cycle for forming HfTaTiO mayinclude sequencing metal-containing precursors in the order of hafnium,tantalum, and titanium in which partial coverage of a monolayer on asubstrate surface is attained for pulsing of a metal-containingprecursor. An ALD cycle for forming HfTaTiO may include sequencing themetal-containing precursors in the order of hafnium, titanium, andtantalum; in the order: tantalum, titanium, and hafnium; in the order:tantalum, hafnium, and tantalum; in the order: titanium, tantalum, andhafnium; or in the order: titanium, hafnium, and tantalum. Oxygenreactant precursors may be applied after pulsing each metal-containingprecursor or after pulsing all the metal-containing precursors.Embodiments for methods for forming hafnium tantalum titanium oxide filmby atomic layer deposition may include numerous permutations of hafniumsequences, tantalum sequences, and titanium sequences for forming ahafnium tantalum titanium oxide film. In an embodiment, ahafnium/tantalum/titanium cycle may include a number, x, of hafniumsequences, a number, y, of tantalum sequences, and a number, z, oftitanium sequences, in which reactant precursors associated with eachmetal are applied with the associated sequence. The number of sequencesx, y, and z may be selected to engineer the relative amounts of hafnium,tantalum, and titanium. In an embodiment, the number of sequences x, y,and z are selected to form a hafnium-rich hafnium tantalum titaniumoxide. Alternatively, the number of sequences x, y, and z are selectedto form a tantalum-rich hafnium tantalum titanium oxide. Additionally,the number of sequences x, y, and z are selected to form a titanium-richhafnium tantalum titanium oxide.

After repeating a selected number of ALD cycles, a determination may bemade as to whether the number of hafnium/tantalum/titanium cycles equalsa predetermined number to form the desired hafnium tantalum titaniumoxide layer. If the total number of cycles to form the desired thicknesshas not been completed, a number of cycles for the hafnium, tantalum,and titanium sequences is repeated. The thickness of a hafnium tantalumtitanium oxide layer formed by atomic layer deposition may be determinedby a fixed growth rate for the pulsing periods and precursors used, setat a value such as N nm/cycle, dependent upon the number of cycles ofthe hafnium/tantalum/titanium sequences. Depending on the precursorsused for ALD formation of a HfTaTiO film, the process may be conductedin an ALD window, which is a range of temperatures in which the growthrate is substantially constant. If such an ALD window is not available,the ALD process may be conducted at the same set of temperatures foreach ALD sequence in the process. For a desired hafnium tantalumtitanium oxide layer thickness, t, in an application, the ALD process isrepeated for t/N total cycles. Once the t/N cycles have completed, nofurther ALD processing for the hafnium tantalum titanium oxide layer isrequired. A hafnium tantalum titanium oxide layer processed atrelatively low temperatures associated with atomic layer deposition mayprovide an amorphous layer.

Either before or after forming a HfTaTiO film in accordance with any ofthe embodiments, other dielectric layers such as nitride layers,dielectric metal silicates, insulating metal oxides including TaO_(y),TiO_(z), HfO_(x), and lanthanide oxides or combinations thereof may beformed as part of a dielectric layer or dielectric stack. These one ormore other layers of dielectric material may be provided instoichiometric form, in non-stoichiometric form, or a combination ofstoichiometric dielectric material and non-stoichiometric dielectricmaterial. Depending on the application, a dielectric stack containing aHfTaTiO_(x) film may include a silicon oxide layer. In an embodiment,the dielectric layer may be formed as a nanolaminate. An embodiment of ananolaminate may include a layer of a hafnium oxide and a HfTaTiO_(x)film, a layer of tantalum oxide and a HfTaTiO_(x) film, a layer oftitanium oxide and a HfTaTiO_(x) film, layers of hafnium oxide, tantalumoxide, and titanium oxide along with a HfTaTiO_(x) film, or variousother combinations. Alternatively, a dielectric layer may be formedsubstantially as the hafnium tantalum titanium oxide film.

In various embodiments, the structure of an interface between adielectric layer and a substrate on which it is disposed is controlledto limit the inclusion of silicon oxide, since a silicon oxide layerwould reduce the effective dielectric constant of the dielectric layer.The material composition and properties for an interface layer may bedependent on process conditions and the condition of the substratebefore forming the dielectric layer. Though the existence of aninterface layer may effectively reduce the dielectric constantassociated with the dielectric layer and its substrate, the interfacelayer, such as a silicon oxide interface layer or other compositioninterface layer, may improve the interface density, fixed chargedensity, and channel mobility of a device having this interface layer.

In an embodiment, the hafnium tantalum titanium oxide layer may be dopedwith other metals. The doping may be employed to enhance the leakagecurrent characteristics of the dielectric layer containing theHfTaTiO_(x) film by providing a disruption or perturbation of thehafnium tantalum titanium oxide structure. Such doping may be realizedby substituting a sequence of one of these metals for a hafniumsequence, a tantalum sequence, a titanium sequence, or variouscombinations of sequences. The choice for substitution may depend on theform of the hafnium tantalum titanium oxide structure with respect tothe relative amounts of hafnium atoms, tantalum atoms, and titaniumatoms desired in the oxide. To maintain a substantially hafnium tantalumtitanium oxide, the amount of dopants inserted into the oxide may belimited to a relatively small fraction of the total number of hafnium,titanium, and tantalum atoms.

In an embodiment, a HfTaTiO_(x) film may be engineered to have adielectric constant, the value of which lies in the range from about 25to about 80. In an embodiment, a HfTaTiO_(x) film may be engineered toprovide a hafnium tantalum titanium oxide film having a dielectricconstant between 40 and 60. In an embodiment, a dielectric layercontaining a hafnium tantalum titanium oxide layer may have a teqranging from about 5 Å to about 20 Å. In an embodiment, a dielectriclayer containing a hafnium tantalum titanium oxide layer may have a teqof less than 5 Å. In an embodiment, a hafnium tantalum titanium oxidefilm may be formed with a thickness ranging from a monolayer tothousands of angstroms. Further, dielectric films of hafnium tantalumtitanium oxide formed by atomic layer deposition may provide not onlythin teq films, but also films with relatively low leakage current.Additionally, embodiments may be implemented to form transistors,capacitors, memory devices, and other electronic systems includinginformation handling devices.

FIG. 2 shows an embodiment of a transistor 200 having a dielectric layer240 containing a HfTaTiO_(x) film. Transistor 200 may include a sourceregion 220 and a drain region 230 in a silicon-based substrate 210 wheresource and drain regions 220, 230 are separated by a body region 232.Body region 232 defines a channel having a channel length 234. A gatedielectric 240 may be disposed on substrate 210 with gate dielectric 240formed as a dielectric layer containing HfTaTiO_(x). Gate dielectric 240may be realized as a dielectric layer formed substantially ofHfTaTiO_(x). Gate dielectric 240 may be constructed as multipledielectric layers, that is, as a dielectric stack, containing at leastone HfTaTiO_(x) film and one or more layers of insulating material otherthan a hafnium tantalum titanium oxide film. The HfTaTiO_(x) film may bestructured as one or more monolayers. An embodiment of a HfTaTiO_(x)film may be formed using atomic layer deposition. A gate 250 may beformed over and contact gate dielectric 240.

An interfacial layer 233 may form between body region 232 and gatedielectric 240. In an embodiment, interfacial layer 233 may be limitedto a relatively small thickness compared to gate dielectric 240, or to athickness significantly less than gate dielectric 240 as to beeffectively eliminated. Forming the substrate and the source and drainregions may be performed using standard processes known to those skilledin the art. Additionally, the sequencing of the various elements of theprocess for forming a transistor may be conducted with fabricationprocesses known to those skilled in the art. In an embodiment, gatedielectric 240 may be realized as a gate insulator in a siliconcomplimentary metal oxide semiconductor (CMOS) transistor. Use of a gatedielectric containing hafnium tantalum titanium oxide is not limited tosilicon based substrates, but may be used with a variety ofsemiconductor substrates.

FIG. 3 shows an embodiment of a floating gate transistor 300 having adielectric layer containing a HfTaTiO_(x) film. The HfTaTiO_(x) film maybe structured as one or more monolayers. The HfTaTiO_(x) film may beformed using atomic layer deposition techniques. Transistor 300 mayinclude a silicon-based substrate 310 with a source 320 and a drain 330separated by a body region 332. Body region 332 between source 320 anddrain 330 defines a channel region having a channel length 334. Locatedabove body region 332 is a stack 355 including a gate dielectric 340, afloating gate 352, a floating gate dielectric 342, and a control gate350. An interfacial layer 333 may form between body region 332 and gatedielectric 340. In an embodiment, interfacial layer 333 may be limitedto a relatively small thickness compared to gate dielectric 340, or to athickness significantly less than gate dielectric 340 as to beeffectively eliminated.

In an embodiment, gate dielectric 340 includes a dielectric containingan atomic layer deposited HfTaTiO_(x) film formed in embodiments similarto those described herein. Gate dielectric 340 may be realized as adielectric layer formed substantially of HfTaTiO_(x). Gate dielectric340 may be a dielectric stack containing at least one HfTaTiO_(x) filmand one or more layers of other insulating materials. In an embodiment,floating gate 352 may be formed over and contact gate dielectric 340.

In an embodiment, floating gate dielectric 342 includes a dielectriccontaining a HfTaTiO_(x) film. The HfTaTiO_(x) film may be structured asone or more monolayers. In an embodiment, the HfTaTiO_(x) may be formedusing atomic layer deposition techniques. Floating gate dielectric 342may be realized as a dielectric layer formed substantially ofHfTaTiO_(x). Floating gate dielectric 342 may be a dielectric stackcontaining at least one HfTaTiO_(x) film and one or more layers of otherinsulating materials. In an embodiment, control gate 350 may be formedover and contact floating gate dielectric 342.

Alternatively, both gate dielectric 340 and floating gate dielectric 342may be formed as dielectric layers containing a HfTaTiO_(x) filmstructured as one or more monolayers. Gate dielectric 340 and floatinggate dielectric 342 may be realized by embodiments similar to thosedescribed herein, with the remaining elements of the transistor 300formed using processes known to those skilled in the art. In anembodiment, gate dielectric 340 forms a tunnel gate insulator andfloating gate dielectric 342 forms an inter-gate insulator in flashmemory devices, where gate dielectric 340 and floating gate dielectric342 may include a hafnium tantalum titanium oxide film structured as oneor more monolayers. Such structures are not limited to silicon basedsubstrates, but may be used with a variety of semiconductor substrates.

Embodiments of a hafnium tantalum titanium oxide film structured as oneor more monolayers may also be applied to capacitors in variousintegrated circuits, memory devices, and electronic systems. In anembodiment for a capacitor 400 illustrated in FIG. 4, a method includesforming a first conductive layer 410, forming a dielectric layer 420containing a hafnium tantalum titanium oxide film structured as one ormore monolayers on first conductive layer 410, and forming a secondconductive layer 430 on dielectric layer 420. Dielectric layer 420,containing a HfTaTiO_(x) film, may be formed using various embodimentsdescribed herein. Dielectric layer 420 may be realized as a dielectriclayer formed substantially of HfTaTiO_(x). Dielectric layer 420 may be adielectric stack containing at least one HfTaTiO_(x) film and one ormore layers of other insulating materials. An interfacial layer 415 mayform between first conductive layer 410 and dielectric layer 420. In anembodiment, interfacial layer 415 may be limited to a relatively smallthickness compared to dielectric layer 420, or to a thicknesssignificantly less than dielectric layer 420 as to be effectivelyeliminated.

Embodiments for a hafnium tantalum titanium oxide film structured as oneor more monolayers may include, but are not limited to, a capacitor in aDRAM and capacitors in analog, radio frequency (RF), and mixed signalintegrated circuits. Mixed signal integrated circuits are integratedcircuits that may operate with digital and analog signals.

FIG. 5 depicts an embodiment of a dielectric structure 500 havingmultiple dielectric layers 505-1, 505-2, . . . 505-N, in which at leastone layer is a hafnium tantalum titanium oxide layer. Layers 510 and 520may provide means to contact dielectric layers 505-1, 505-2, . . .505-N. Layers 510 and 520 may be electrodes forming a capacitor. Layer510 may be a body region of a transistor with layer 520 being a gate.Layer 510 may be a floating gate electrode with layer 520 being acontrol gate.

In an embodiment, dielectric structure 500 includes one or more layers505-1, 505-2 . . . 505-N as dielectric layers other than a HfTaTiOlayer, where at least one layer is a HfTaTiO layer. Dielectric layers505-1, 505-2 . . . 505-N may include a HfO_(x) layer, a TaO_(y) layer, aTiO_(z) layer, a HfTiO layer, a HfTaO layer, a TaTiO layer, or variouscombinations of these layers. Dielectric layers 505-1, 505-2 . . . 505-Nmay include an insulating metal oxide layer, whose metal is selected tobe a metal different from hafnium, tantalum and titanium. Dielectriclayers 505-1, 505-2, . . . 505-N may include an insulating nitridelayer. Dielectric layers 505-1, 505-2, . . . 505-N may include aninsulating oxynitride layer. Dielectric layers 505-1, 505-2, . . . 505-Nmay include a silicon nitride layer. Dielectric layers 505-1, 505-2, . .. 505-N may include an insulating silicate layer. Dielectric layers505-1, 505-2, . . . 505-N may include a silicon oxide layer.

Various embodiments for a dielectric layer containing a hafnium tantalumtitanium oxide film structured as one or more monolayers may provide forenhanced device performance by providing devices with reduced leakagecurrent. Such improvements in leakage current characteristics may beattained by forming one or more layers of a hafnium tantalum titaniumoxide in a nanolaminate structure with other metal oxides,non-metal-containing dielectrics, or combinations thereof. Thetransition from one layer of the nanolaminate to another layer of thenanolaminate provides disruption to a tendency for an ordered structurein the nanolaminate stack. The term “nanolaminate” means a compositefilm of ultra thin layers of two or more materials in a layered stack.Typically, each layer in a nanolaminate has a thickness of an order ofmagnitude in the nanometer range. Further, each individual materiallayer of the nanolaminate may have a thickness as low as a monolayer ofthe material or as high as 20 nanometers. In an embodiment, aHfO_(x)/HfTaTiO nanolaminate contains alternating layers of a hafniumoxide and HfTaTiO. In an embodiment, a TaO_(y)/HfTaTiO nanolaminatecontains alternating layers of tantalum oxide and HfTaTiO. In anembodiment, a TiO_(z)/HfTaTiO nanolaminate contains alternating layersof titanium oxide and HfTaTiO. In an embodiment, aHfO_(x)/TaO_(y)/TiO_(z)/HfTaTiO nanolaminate contains variouspermutations of hafnium oxide layers, tantalum oxide layers, titaniumoxide layers, and hafnium tantalum titanium oxide layers.

In an embodiment, dielectric structure 500 may be structured as ananolaminate structure 500 including a HfTaTiO_(x) film structured asone or more monolayers. Nanolaminate structure 500 includes a pluralityof layers 505-1, 505-2 to 505-N, where at least one layer contains aHfTaTiO_(x) film structured as one or more monolayers. The other layersmay be insulating nitrides, insulating oxynitrides, and other dielectricmaterials such as insulating metal oxides. The sequencing of the layersdepends on the application. The effective dielectric constant associatedwith nanolaminate structure 500 is that attributable to N capacitors inseries, where each capacitor has a thickness defined by the thicknessand composition of the corresponding layer. By selecting each thicknessand the composition of each layer, a nanolaminate structure can beengineered to have a predetermined dielectric constant. Embodiments forstructures such as nanolaminate structure 500 may be used asnanolaminate dielectrics in non-volatile read only memory (NROM) flashmemory devices as well as other integrated circuits. In an embodiment, alayer of the nanolaminate structure 500 is used to store charge in aNROM device. The charge storage layer of a nanolaminate structure 500 ina NROM device may be a silicon oxide layer.

Transistors, capacitors, and other devices may include dielectric filmscontaining a layer of a hafnium tantalum titanium oxide compoundstructured as one or more monolayers. The hafnium tantalum titaniumoxide layer may be formed by atomic layer deposition. Dielectric filmscontaining a hafnium tantalum titanium oxide layer may be implementedinto memory devices and electronic systems including informationhandling devices. Further, embodiments of electronic devices andelectronic apparatus may be realized as integrated circuits. Embodimentsof information handling devices may include wireless systems,telecommunication systems, and computers.

FIG. 6 illustrates a block diagram for an electronic system 600 havingone or more devices having a dielectric structure including aHfTaTiO_(x) film structured as one or more monolayers. Electronic system600 includes a controller 605, a bus 615, and an electronic device 625,where bus 615 provides electrical conductivity between controller 605and electronic device 625. In various embodiments, controller 605 mayinclude an embodiment of a HfTaTiO_(x) film. In various embodiments,electronic device 625 may include an embodiment of a HfTaTiO_(x) film.In various embodiments, controller 605 and electronic device 625 mayinclude embodiments of a HfTaTiO_(x) film. Electronic system 600 mayinclude, but is not limited to, fiber optic systems, electro-opticsystems, and information handling systems such as wireless systems,telecommunication systems, and computers.

FIG. 7 depicts a diagram of an embodiment of a system 700 having acontroller 705 and a memory 725. Controller 705 may include aHfTaTiO_(x) film structured as one or more monolayers. Memory 725 mayinclude a HfTaTiO_(x) film structured as one or more monolayers.Controller 705 and memory 725 may each include a HfTaTiO_(x) filmstructured as one or more monolayers. System 700 also includes anelectronic apparatus 735 and a bus 715, where bus 715 provideselectrical conductivity between controller 705 and electronic apparatus735, and between controller 705 and memory 725. Bus 715 may include anaddress bus, a data bus, and a control bus, each independentlyconfigured. Alternatively, bus 715 may use common conductive lines forproviding one or more of address, data, or control, the use of which isregulated by controller 705. In an embodiment, electronic apparatus 735may be additional memory configured in a manner similar to memory 725.An embodiment may include an additional peripheral device or devices 745coupled to bus 715. In an embodiment, controller 705 is a processor. Oneor more of controller 705, memory 725, bus 715, electronic apparatus735, or peripheral devices 745 may include an embodiment of a dielectriclayer having a HfTaTiO_(x) film structured as one or more monolayersSystem 700 may include, but is not limited to, information handlingdevices, telecommunication systems, and computers.

Peripheral devices 745 may include displays, additional storage memory,or other control devices that may operate in conjunction with controller705. Alternatively, peripheral devices 745 may include displays,additional storage memory, or other control devices that may operate inconjunction with memory 725, or controller 705 and memory 725.

Memory 725 may be realized as a memory device containing a HfTaTiO_(x)film structured as one or more monolayers. The HfTaTiO_(x) structure maybe formed in a memory cell of a memory array. The HfTaTiO_(x) oxidestructure may be formed in a capacitor in a memory cell of a memoryarray. The HfTaTiO_(x) structure may be formed in a transistor in amemory cell of a memory array. It will be understood that embodimentsare equally applicable to any size and type of memory circuit and arenot intended to be limited to a particular type of memory device. Memorytypes include a DRAM, SRAM (Static Random Access Memory) or Flashmemories. Additionally, the DRAM could be a synchronous DRAM commonlyreferred to as SGRAM (Synchronous Graphics Random Access Memory), SDRAM(Synchronous Dynamic Random Access Memory), SDRAM II, and DDR SDRAM(Double Data Rate SDRAM), as well as other emerging DRAM technologies.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement that is calculated to achieve the same purpose maybe substituted for the specific embodiments shown. It is to beunderstood that the above description is intended to be illustrative,and not restrictive, and that the phraseology or terminology employedherein is for the purpose of description and not of limitation.Combinations of the above embodiments and other embodiments will beapparent to those of skill in the art upon studying the abovedescription.

What is claimed is:
 1. A method for forming a transistor, the methodcomprising: forming a source region in a substrate; forming a drainregion in the substrate; forming a dielectric on the substrate, with areaction sequence atomic layer deposition process, the dielectricincluding a hafnium tantalum titanium oxide, a hafnium oxide, a tantalumoxide, and a titanium oxide as separate entities; and forming a gateabove the dielectric.
 2. The transistor of claim 1, wherein forming thedielectric includes a dielectric nitride.
 3. The transistor of claim 1,wherein forming the dielectric includes forming an insulating metaloxide layer, whose metal is different from hafnium, tantalum andtitanium.
 4. The transistor of claim 1, further comprising forming aninterfacial material between the substrate and the dielectric.
 5. Thetransistor of claim 4, wherein forming the interfacial materialcomprises forming the interfacial layer to a thickness that is less thanthe dielectric.
 6. The transistor of claim 1, wherein forming thedielectric comprises forming a tunnel oxide contacting a channel and afloating gate in the transistor.
 7. The transistor of claim 1, whereinforming the dielectric comprises forming a floating gate dielectriccontacting a floating gate and the gate in the transistor.
 8. A methodfor forming a transistor, the method comprising: forming a source regionin a substrate; forming a drain region in the substrate; forming adielectric on the substrate with a reaction sequence atomic layerdeposition process, the process including doping a hafnium tantalumtitanium oxide with a metal or a compound of two or more differentelements, the metal being different from hafnium, tantalum, andtitanium; and forming a control gate on the dielectric.
 9. Thetransistor of claim 8, further comprising forming a capacitor having thedielectric arranged between two conductive materials of the capacitor.10. The transistor of claim 8, wherein forming the dielectric comprisesforming the dielectric disposed as a tunnel oxide of the transistor. 11.The transistor of claim 8, wherein forming the dielectric comprisesforming a nanolaminate containing the doped hafnium tantalum titaniumoxide.
 12. The transistor of claim 11, further comprising forming thenanolaminate with a silicon oxide layer.
 13. The transistor of claim 11,further comprising forming the nanolaminate as one or more layers ofhafnium oxide, tantalum oxide, titanium oxide, hafnium titanium oxide,hafnium tantalum oxide, or tantalum titanium oxide.
 14. The transistorof claim 11, further comprising forming the nanolaminate with aninsulating oxynitride layer.
 15. A method for forming a transistor, themethod comprising: forming a source region in a substrate; forming adrain region in the substrate; forming a dielectric on the substrateusing a reaction sequence atomic layer deposition process, the processincluding forming a layer of hafnium tantalum titanium oxide by cyclescomprising forming hafnium oxide material, tantalum oxide material, andtitanium oxide material, each oxide material formed independent of eachother, and annealing the oxide materials such that hafnium tantalumtitanium oxide is formed; and forming a gate on the dielectric.
 16. Themethod of claim 15, wherein forming the hafnium tantalum titanium oxideincludes using a monolayer or partial monolayer sequencing process. 17.The method of claim 16, wherein forming the hafnium tantalum titaniumoxide includes doping by substituting a sequence of dopant material forone of a hafnium sequence, a tantalum sequence, or a titanium sequencein a cycle of the monolayer or partial monolayer sequencing process. 18.The method of claim 16, and further comprising using a titanium halideprecursor.
 19. The method of claim 18, wherein using the titanium halideprecursor comprises using a titanium chloride precursor.
 20. The methodof claim 15, wherein forming the dielectric includes using a hafniumnitride precursor.